The years go by and you find yourself still using the same child restraint system. It gets passed down from child to child between friends and family. Unfortunately, you need to be aware that time and usage can take their toll. This is what has been demonstrated in tests run by Fundación MAPFRE to support its 2016 report on children's road safety in cars in Spain and Latin America.
You should be aware that aging or damaged car seats do not offer the same level of protection and could even break due to the deceleration experienced in a collision or car accident.
Fundación MAPFRE ran a trial on this subject to check if aging CRS really do continue to be effective. A Group I (10-18 kg) car seat was used and a P3 dummy.
The car seat was installed in a forward-facing position. It was, however, previously subjected to an accelerated aging process. This was achieved by performing 8 cycles lasting a total of 96 hours: 1 cycle of 12 hours included rising and falling temperatures over long and short periods of time. The maximum temperature was set at 80ºC at humidity at 30%.
After this, a crash test was undertaken at a trial speed of 48.59 km/h with a stopping distance of sled of 645 mm.
The tests showed acceleration values for the head and chest that exceeded statutory limits, although it must be pointed out that the CRS did not suffer from any breakage or abnormal displacement. On this matter, the report points out that 'the non-statutory values registered might be caused by changes in properties such as the rigidity of the CRS material due to aging'.
Specifically, horizontal and vertical displacement fell within the maximum values dictated by R44. The results were 542 mm for horizontal displacement and 708 mm for vertical displacement. R44 specifies 550 mm and 800 mm respectively.
When it comes to sensors, the data show a high spike in the case of chest acceleration. In this case the maximum value is 38.95g, while the officially approved standard limits vertical acceleration to a value below 30 g (this value may be exceed if it lasts less than 3 ms).
The Euro NCAP Assessment Protocol - Child Occupant Protection was used as a reference to evaluate head acceleration. Here, it is understood that a value in excess of 80 g implies there has been head contact. If the acceleration spike is higher than 88 g for over 3 ms, the result obtained is considered as invalid.
The trial showed a maximum spike of 110.24g indicating that there had been contact with the head. Another spike of 99 g was registered lasting between 240 and 250 ms, thus exceeding the regulatory 88 g.
The report reveals that having observed a spike in excess of 99 g, and for over 3 ms, there is a 50% probability value of sustaining a severe injury (AIS 3).
Here we can see the crash test being performed:
The dossier compiled by Fundación MAPFRE also includes data from crash tests performed to see what happens if you travel with a child on your lap or with a slacker than normal seat belt. Check here to discover the consequences of using a child restraint system incorrectly.
Fundación MAPFRE's Accident Prevention and Road Safety Area advocates the recycling of aging child restraint systems. Thus, a change of car seat is recommended every 6 years. It is even better if done sooner, especially if the child grows out of the seat, a sure sign that it will not offer adequate protection. Continuous use, the passage of time, being employed in situations of sharp braking - in the article ‘Recycling child restraint systems when they are of no further use' we discuss the reasons that might lead to us changing a child seat.